The applicant previously proposed a keyboard having a plurality of whole-tone arrangement keyboard rows which are disposed in a staggered manner (Japanese Utility Model Laid-open Pub. No. Sho63-43196).
The above conventional keyboard suffers from a deficiency of being unsuited to glissando although it allows tunes in any key scale to be played with the same fingering as in C major, due to its keyboard configuration in which are staggered the plurality of whole-tone arrangement keyboard rows.
When fingers slide laterally, a series of consecutive tones are played with a difference of whole tone. On the contrary, to obtain a series of consecutive tones with a difference of semitone, the fingers are diagonally slid from the rear keyboard row toward the front keyboard row. In this case, if five keyboard rows are present, the series of consecutive tones contains only five tones, which means that the number of tones contained in the series of consecutive tones becomes equal to the number of keyboard rows.
In the event of playing a piece of music with the keyboard having a plurality of whole-tone arrangement keyboard rows which are disposed in a staggered manner, players familiar with an ordinary keyboard composed of white keys and black keys in major scale arrangement (hereinafter referred to simply as “ordinary keyboard”) may be difficult to handle due to its largely different fingering from the case of playing with the ordinary keyboard.